diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/kernel/xloop_main.c | 8 | ||||
| -rw-r--r-- | src/kernel/xloop_main.h | 11 | ||||
| -rw-r--r-- | src/kernel/xloop_main_4.18.c | 9 | ||||
| -rw-r--r-- | src/kernel/xloop_main_5.15.c | 2 | ||||
| -rw-r--r-- | src/kernel/xloop_main_rhel_8.5.c | 2111 | ||||
| -rw-r--r-- | src/kernel/xloop_main_rhel_8.5.h | 104 |
6 files changed, 2231 insertions, 14 deletions
diff --git a/src/kernel/xloop_main.c b/src/kernel/xloop_main.c index b3f7963..cd1a767 100644 --- a/src/kernel/xloop_main.c +++ b/src/kernel/xloop_main.c @@ -1,6 +1,10 @@ -#include <linux/version.h> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt -#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 15, 0) +#include "xloop_main.h" + +#if RHEL_CHECK_VERSION(RHEL_RELEASE_CODE >= RHEL_RELEASE_VERSION(8, 5)) +#include "xloop_main_rhel_8.5.c" +#elif LINUX_VERSION_CODE < KERNEL_VERSION(5, 15, 0) #include "xloop_main_4.18.c" #else #include "xloop_main_5.15.c" diff --git a/src/kernel/xloop_main.h b/src/kernel/xloop_main.h index c1cc919..3649039 100644 --- a/src/kernel/xloop_main.h +++ b/src/kernel/xloop_main.h @@ -1,6 +1,15 @@ #include <linux/version.h> -#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 15, 0) +/* define RHEL_CHECK_VERSION macro to check CentOS version */ +#if defined(RHEL_RELEASE_CODE) && defined(RHEL_RELEASE_VERSION) +#define RHEL_CHECK_VERSION(CONDITION) (CONDITION) +#else +#define RHEL_CHECK_VERSION(CONDITION) (0) +#endif + +#if RHEL_CHECK_VERSION(RHEL_RELEASE_CODE >= RHEL_RELEASE_VERSION(8, 5)) +#include "xloop_main_rhel_8.5.h" +#elif LINUX_VERSION_CODE < KERNEL_VERSION(5, 15, 0) #include "xloop_main_4.18.h" #else #include "xloop_main_5.15.h" diff --git a/src/kernel/xloop_main_4.18.c b/src/kernel/xloop_main_4.18.c index 9fe0c70..dde0ad0 100644 --- a/src/kernel/xloop_main_4.18.c +++ b/src/kernel/xloop_main_4.18.c @@ -53,8 +53,6 @@ * */ -#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt - #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/sched.h> @@ -96,13 +94,6 @@ #include <linux/uaccess.h> -/* define RHEL_CHECK_VERSION macro to check CentOS version */ -#if defined(RHEL_RELEASE_CODE) && defined(RHEL_RELEASE_VERSION) -#define RHEL_CHECK_VERSION(CONDITION) (CONDITION) -#else -#define RHEL_CHECK_VERSION(CONDITION) (0) -#endif - static DEFINE_IDR(xloop_index_idr); static DEFINE_MUTEX(xloop_ctl_mutex); diff --git a/src/kernel/xloop_main_5.15.c b/src/kernel/xloop_main_5.15.c index d133709..9866c2b 100644 --- a/src/kernel/xloop_main_5.15.c +++ b/src/kernel/xloop_main_5.15.c @@ -53,8 +53,6 @@ * */ -#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt - #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/sched.h> diff --git a/src/kernel/xloop_main_rhel_8.5.c b/src/kernel/xloop_main_rhel_8.5.c new file mode 100644 index 0000000..eb1538e --- /dev/null +++ b/src/kernel/xloop_main_rhel_8.5.c @@ -0,0 +1,2111 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * xloop_main.c + * + * Written by Theodore Ts'o, 3/29/93 + * + * Copyright 1993 by Theodore Ts'o. Redistribution of this file is + * permitted under the GNU General Public License. + * + * DES encryption plus some minor changes by Werner Almesberger, 30-MAY-1993 + * more DES encryption plus IDEA encryption by Nicholas J. Leon, June 20, 1996 + * + * Modularized and updated for 1.1.16 kernel - Mitch Dsouza 28th May 1994 + * Adapted for 1.3.59 kernel - Andries Brouwer, 1 Feb 1996 + * + * Fixed do_xloop_request() re-entrancy - Vincent.Renardias@waw.com Mar 20, 1997 + * + * Added devfs support - Richard Gooch <rgooch@atnf.csiro.au> 16-Jan-1998 + * + * Handle sparse backing files correctly - Kenn Humborg, Jun 28, 1998 + * + * Loadable modules and other fixes by AK, 1998 + * + * Make real block number available to downstream transfer functions, enables + * CBC (and relatives) mode encryption requiring unique IVs per data block. + * Reed H. Petty, rhp@draper.net + * + * Maximum number of xloop devices now dynamic via max_xloop module parameter. + * Russell Kroll <rkroll@exploits.org> 19990701 + * + * Maximum number of xloop devices when compiled-in now selectable by passing + * max_xloop=<1-255> to the kernel on boot. + * Erik I. Bolsø, <eriki@himolde.no>, Oct 31, 1999 + * + * Completely rewrite request handling to be make_request_fn style and + * non blocking, pushing work to a helper thread. Lots of fixes from + * Al Viro too. + * Jens Axboe <axboe@suse.de>, Nov 2000 + * + * Support up to 256 xloop devices + * Heinz Mauelshagen <mge@sistina.com>, Feb 2002 + * + * Support for falling back on the write file operation when the address space + * operations write_begin is not available on the backing filesystem. + * Anton Altaparmakov, 16 Feb 2005 + * + * Support for using file formats. + * Manuel Bentele <development@manuel-bentele.de>, 2019 + * + * Still To Fix: + * - Advisory locking is ignored here. + * - Should use an own CAP_* category instead of CAP_SYS_ADMIN + * + */ + +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/sched.h> +#include <linux/fs.h> +#include <linux/file.h> +#include <linux/stat.h> +#include <linux/errno.h> +#include <linux/major.h> +#include <linux/wait.h> +#include <linux/blkdev.h> +#include <linux/blkpg.h> +#include <linux/init.h> +#include <linux/swap.h> +#include <linux/slab.h> +#include <linux/compat.h> +#include <linux/suspend.h> +#include <linux/freezer.h> +#include <linux/mutex.h> +#include <linux/writeback.h> +#include <linux/completion.h> +#include <linux/highmem.h> +#include <linux/kthread.h> +#include <linux/splice.h> +#include <linux/sysfs.h> +#include <linux/miscdevice.h> +#include <linux/falloc.h> +#include <linux/uio.h> +#include <linux/ioprio.h> +#include <linux/blk-cgroup.h> +#include <linux/version.h> +#ifdef CONFIG_DEBUG_FS +#include <linux/debugfs.h> +#endif + +#include <xloop/version.h> + +#include "xloop_file_fmt.h" +#include "xloop_main.h" + +#include <linux/uaccess.h> + +static DEFINE_IDR(xloop_index_idr); +static DEFINE_MUTEX(xloop_ctl_mutex); + +static int max_part; +static int part_shift; + +struct device *xloop_device_to_dev(struct xloop_device *xlo) +{ + return disk_to_dev(xlo->xlo_disk); +} +EXPORT_SYMBOL(xloop_device_to_dev); + +static int transfer_xor(struct xloop_device *xlo, int cmd, struct page *raw_page, unsigned int raw_off, + struct page *xloop_page, unsigned int xloop_off, int size, sector_t real_block) +{ + char *raw_buf = kmap_atomic(raw_page) + raw_off; + char *xloop_buf = kmap_atomic(xloop_page) + xloop_off; + char *in, *out, *key; + int i, keysize; + + if (cmd == READ) { + in = raw_buf; + out = xloop_buf; + } else { + in = xloop_buf; + out = raw_buf; + } + + key = xlo->xlo_encrypt_key; + keysize = xlo->xlo_encrypt_key_size; + for (i = 0; i < size; i++) + *out++ = *in++ ^ key[(i & 511) % keysize]; + + kunmap_atomic(xloop_buf); + kunmap_atomic(raw_buf); + cond_resched(); + return 0; +} + +static int xor_init(struct xloop_device *xlo, const struct xloop_info64 *info) +{ + if (unlikely(info->xlo_encrypt_key_size <= 0)) + return -EINVAL; + return 0; +} + +static struct xloop_func_table none_funcs = { + .number = XLO_CRYPT_NONE, +}; + +static struct xloop_func_table xor_funcs = { .number = XLO_CRYPT_XOR, .transfer = transfer_xor, .init = xor_init }; + +/* xfer_funcs[0] is special - its release function is never called */ +static struct xloop_func_table *xfer_funcs[MAX_XLO_CRYPT] = { &none_funcs, &xor_funcs }; + +static loff_t get_xloop_size(struct xloop_device *xlo, struct file *file) +{ + return xloop_file_fmt_sector_size(xlo->xlo_fmt, file, xlo->xlo_offset, xlo->xlo_sizelimit); +} + +static void __xloop_update_dio(struct xloop_device *xlo, bool dio) +{ + struct file *file = xlo->xlo_backing_file; + struct address_space *mapping = file->f_mapping; + struct inode *inode = mapping->host; + unsigned short sb_bsize = 0; + unsigned int dio_align = 0; + bool use_dio; + + if (inode->i_sb->s_bdev) { + sb_bsize = bdev_logical_block_size(inode->i_sb->s_bdev); + dio_align = sb_bsize - 1; + } + + /* + * We support direct I/O only if xlo_offset is aligned with the + * logical I/O size of backing device, and the logical block + * size of xloop is bigger than the backing device's and the xloop + * needn't transform transfer. + * + * TODO: the above condition may be loosed in the future, and + * direct I/O may be switched runtime at that time because most + * of requests in sane applications should be PAGE_SIZE aligned + */ + if (dio) { + if (queue_logical_block_size(xlo->xlo_queue) >= sb_bsize && !(xlo->xlo_offset & dio_align) && + mapping->a_ops->direct_IO && !xlo->transfer) + use_dio = true; + else + use_dio = false; + } else { + use_dio = false; + } + + if (xlo->use_dio == use_dio) + return; + + /* flush dirty pages before changing direct IO */ + xloop_file_fmt_flush(xlo->xlo_fmt); + + /* + * The flag of XLO_FLAGS_DIRECT_IO is handled similarly with + * XLO_FLAGS_READ_ONLY, both are set from kernel, and losetup + * will get updated by ioctl(XLOOP_GET_STATUS) + */ + if (xlo->xlo_state == Xlo_bound) + blk_mq_freeze_queue(xlo->xlo_queue); + xlo->use_dio = use_dio; + if (use_dio) { + blk_queue_flag_clear(QUEUE_FLAG_NOMERGES, xlo->xlo_queue); + xlo->xlo_flags |= XLO_FLAGS_DIRECT_IO; + } else { + blk_queue_flag_set(QUEUE_FLAG_NOMERGES, xlo->xlo_queue); + xlo->xlo_flags &= ~XLO_FLAGS_DIRECT_IO; + } + if (xlo->xlo_state == Xlo_bound) + blk_mq_unfreeze_queue(xlo->xlo_queue); +} + +/** + * xloop_validate_block_size() - validates the passed in block size + * @bsize: size to validate + */ +static int xloop_validate_block_size(unsigned short bsize) +{ + if (bsize < 512 || bsize > PAGE_SIZE || !is_power_of_2(bsize)) + return -EINVAL; + + return 0; +} + +/** + * xloop_set_size() - sets device size and notifies userspace + * @xlo: struct xloop_device to set the size for + * @size: new size of the xloop device + * + * Callers must validate that the size passed into this function fits into + * a sector_t, eg using xloop_validate_size() + */ +static void xloop_set_size(struct xloop_device *xlo, loff_t size) +{ + struct block_device *bdev = xlo->xlo_device; + + bd_set_nr_sectors(bdev, size); + + if (!set_capacity_revalidate_and_notify(xlo->xlo_disk, size, false)) + kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, KOBJ_CHANGE); +} + +static void xlo_complete_rq(struct request *rq) +{ + struct xloop_cmd *cmd = blk_mq_rq_to_pdu(rq); + blk_status_t ret = BLK_STS_OK; + + if (!cmd->use_aio || cmd->ret < 0 || cmd->ret == blk_rq_bytes(rq) || req_op(rq) != REQ_OP_READ) { + if (cmd->ret < 0) + ret = errno_to_blk_status(cmd->ret); + goto end_io; + } + + /* + * Short READ - if we got some data, advance our request and + * retry it. If we got no data, end the rest with EIO. + */ + if (cmd->ret) { + blk_update_request(rq, BLK_STS_OK, cmd->ret); + cmd->ret = 0; + blk_mq_requeue_request(rq, true); + } else { + if (cmd->use_aio) { + struct bio *bio = rq->bio; + + while (bio) { + zero_fill_bio(bio); + bio = bio->bi_next; + } + } + ret = BLK_STS_IOERR; +end_io: + blk_mq_end_request(rq, ret); + } +} + +static int do_req_filebacked(struct xloop_device *xlo, struct request *rq) +{ + struct xloop_cmd *cmd = blk_mq_rq_to_pdu(rq); + + /* + * xlo_write_simple and xlo_read_simple should have been covered + * by io submit style function like xlo_rw_aio(), one blocker + * is that xlo_read_simple() need to call flush_dcache_page after + * the page is written from kernel, and it isn't easy to handle + * this in io submit style function which submits all segments + * of the req at one time. And direct read IO doesn't need to + * run flush_dcache_page(). + */ + switch (req_op(rq)) { + case REQ_OP_FLUSH: + return xloop_file_fmt_flush(xlo->xlo_fmt); + case REQ_OP_WRITE_ZEROES: + return xloop_file_fmt_write_zeros(xlo->xlo_fmt, rq); + case REQ_OP_DISCARD: + return xloop_file_fmt_discard(xlo->xlo_fmt, rq); + case REQ_OP_WRITE: + if (cmd->use_aio) + return xloop_file_fmt_write_aio(xlo->xlo_fmt, rq); + else + return xloop_file_fmt_write(xlo->xlo_fmt, rq); + case REQ_OP_READ: + if (cmd->use_aio) + return xloop_file_fmt_read_aio(xlo->xlo_fmt, rq); + else + return xloop_file_fmt_read(xlo->xlo_fmt, rq); + default: + WARN_ON_ONCE(1); + return -EIO; + } +} + +static inline void xloop_update_dio(struct xloop_device *xlo) +{ + __xloop_update_dio(xlo, (xlo->xlo_backing_file->f_flags & O_DIRECT) | xlo->use_dio); +} + +static void xloop_reread_partitions(struct xloop_device *xlo, struct block_device *bdev) +{ + int rc; + + mutex_lock(&bdev->bd_mutex); + rc = bdev_disk_changed(bdev, false); + mutex_unlock(&bdev->bd_mutex); + if (rc) + dev_warn(xloop_device_to_dev(xlo), "partition scan failed (rc=%d)\n", rc); +} + +static inline int is_xloop_device(struct file *file) +{ + struct inode *i = file->f_mapping->host; + + return i && S_ISBLK(i->i_mode) && MAJOR(i->i_rdev) == XLOOP_MAJOR; +} + +static int xloop_validate_file(struct file *file, struct block_device *bdev) +{ + struct inode *inode = file->f_mapping->host; + struct file *f = file; + + /* Avoid recursion */ + while (is_xloop_device(f)) { + struct xloop_device *l; + + if (f->f_mapping->host->i_bdev == bdev) + return -EBADF; + + l = f->f_mapping->host->i_bdev->bd_disk->private_data; + if (l->xlo_state != Xlo_bound) + return -EINVAL; + + f = l->xlo_backing_file; + } + if (!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode)) + return -EINVAL; + return 0; +} + +/* + * xloop_change_fd switched the backing store of a xloopback device to + * a new file. This is useful for operating system installers to free up + * the original file and in High Availability environments to switch to + * an alternative location for the content in case of server meltdown. + * This can only work if the xloop device is used read-only, and if the + * new backing store is the same size and type as the old backing store. + */ +static int xloop_change_fd(struct xloop_device *xlo, struct block_device *bdev, unsigned int arg) +{ + struct file *file = NULL, *old_file; + int error; + bool partscan; + + error = mutex_lock_killable(&xloop_ctl_mutex); + if (error) + return error; + error = -ENXIO; + if (xlo->xlo_state != Xlo_bound) + goto out_err; + + /* the xloop device has to be read-only */ + error = -EINVAL; + if (!(xlo->xlo_flags & XLO_FLAGS_READ_ONLY)) + goto out_err; + + error = -EBADF; + file = fget(arg); + if (!file) + goto out_err; + + error = xloop_validate_file(file, bdev); + if (error) + goto out_err; + + old_file = xlo->xlo_backing_file; + + error = -EINVAL; + + /* size of the new backing store needs to be the same */ + if (get_xloop_size(xlo, file) != get_xloop_size(xlo, old_file)) + goto out_err; + + /* and ... switch */ + blk_mq_freeze_queue(xlo->xlo_queue); + mapping_set_gfp_mask(old_file->f_mapping, xlo->old_gfp_mask); + xlo->xlo_backing_file = file; + xlo->old_gfp_mask = mapping_gfp_mask(file->f_mapping); + mapping_set_gfp_mask(file->f_mapping, xlo->old_gfp_mask & ~(__GFP_IO | __GFP_FS)); + xloop_update_dio(xlo); + blk_mq_unfreeze_queue(xlo->xlo_queue); + partscan = xlo->xlo_flags & XLO_FLAGS_PARTSCAN; + mutex_unlock(&xloop_ctl_mutex); + /* + * We must drop file reference outside of xloop_ctl_mutex as dropping + * the file ref can take bd_mutex which creates circular locking + * dependency. + */ + fput(old_file); + if (partscan) + xloop_reread_partitions(xlo, bdev); + return 0; + +out_err: + mutex_unlock(&xloop_ctl_mutex); + if (file) + fput(file); + return error; +} + +/* xloop sysfs attributes */ + +static ssize_t xloop_attr_show(struct device *dev, char *page, ssize_t (*callback)(struct xloop_device *, char *)) +{ + struct gendisk *disk = dev_to_disk(dev); + struct xloop_device *xlo = disk->private_data; + + return callback(xlo, page); +} + +#define XLOOP_ATTR_RO(_name) \ + static ssize_t xloop_attr_##_name##_show(struct xloop_device *, char *); \ + static ssize_t xloop_attr_do_show_##_name(struct device *d, struct device_attribute *attr, char *b) \ + { \ + return xloop_attr_show(d, b, xloop_attr_##_name##_show); \ + } \ + static struct device_attribute xloop_attr_##_name = __ATTR(_name, 0444, xloop_attr_do_show_##_name, NULL); + +static ssize_t xloop_attr_backing_file_show(struct xloop_device *xlo, char *buf) +{ + ssize_t ret; + char *p = NULL; + + spin_lock_irq(&xlo->xlo_lock); + if (xlo->xlo_backing_file) + p = file_path(xlo->xlo_backing_file, buf, PAGE_SIZE - 1); + spin_unlock_irq(&xlo->xlo_lock); + + if (IS_ERR_OR_NULL(p)) + ret = PTR_ERR(p); + else { + ret = strlen(p); + memmove(buf, p, ret); + buf[ret++] = '\n'; + buf[ret] = 0; + } + + return ret; +} + +static ssize_t xloop_attr_file_fmt_type_show(struct xloop_device *xlo, char *buf) +{ + ssize_t len = 0; + + len = xloop_file_fmt_print_type(xlo->xlo_fmt->file_fmt_type, buf); + len += sprintf(buf + len, "\n"); + + return len; +} + +static ssize_t xloop_attr_offset_show(struct xloop_device *xlo, char *buf) +{ + return sprintf(buf, "%llu\n", (unsigned long long)xlo->xlo_offset); +} + +static ssize_t xloop_attr_sizelimit_show(struct xloop_device *xlo, char *buf) +{ + return sprintf(buf, "%llu\n", (unsigned long long)xlo->xlo_sizelimit); +} + +static ssize_t xloop_attr_autoclear_show(struct xloop_device *xlo, char *buf) +{ + int autoclear = (xlo->xlo_flags & XLO_FLAGS_AUTOCLEAR); + + return sprintf(buf, "%s\n", autoclear ? "1" : "0"); +} + +static ssize_t xloop_attr_partscan_show(struct xloop_device *xlo, char *buf) +{ + int partscan = (xlo->xlo_flags & XLO_FLAGS_PARTSCAN); + + return sprintf(buf, "%s\n", partscan ? "1" : "0"); +} + +static ssize_t xloop_attr_dio_show(struct xloop_device *xlo, char *buf) +{ + int dio = (xlo->xlo_flags & XLO_FLAGS_DIRECT_IO); + + return sprintf(buf, "%s\n", dio ? "1" : "0"); +} + +XLOOP_ATTR_RO(backing_file); +XLOOP_ATTR_RO(file_fmt_type); +XLOOP_ATTR_RO(offset); +XLOOP_ATTR_RO(sizelimit); +XLOOP_ATTR_RO(autoclear); +XLOOP_ATTR_RO(partscan); +XLOOP_ATTR_RO(dio); + +static struct attribute *xloop_attrs[] = { + &xloop_attr_backing_file.attr, &xloop_attr_file_fmt_type.attr, + &xloop_attr_offset.attr, &xloop_attr_sizelimit.attr, + &xloop_attr_autoclear.attr, &xloop_attr_partscan.attr, + &xloop_attr_dio.attr, NULL, +}; + +static struct attribute_group xloop_attribute_group = { + .name = "xloop", + .attrs = xloop_attrs, +}; + +static void xloop_sysfs_init(struct xloop_device *xlo) +{ + xlo->sysfs_inited = !sysfs_create_group(&disk_to_dev(xlo->xlo_disk)->kobj, &xloop_attribute_group); +} + +static void xloop_sysfs_exit(struct xloop_device *xlo) +{ + if (xlo->sysfs_inited) + sysfs_remove_group(&disk_to_dev(xlo->xlo_disk)->kobj, &xloop_attribute_group); +} + +static void xloop_config_discard(struct xloop_device *xlo) +{ + struct file *file = xlo->xlo_backing_file; + struct inode *inode = file->f_mapping->host; + struct request_queue *q = xlo->xlo_queue; + u32 granularity, max_discard_sectors; + + /* + * If the backing device is a block device, mirror its zeroing + * capability. Set the discard sectors to the block device's zeroing + * capabilities because xloop discards result in blkdev_issue_zeroout(), + * not blkdev_issue_discard(). This maintains consistent behavior with + * file-backed xloop devices: discarded regions read back as zero. + */ + if (S_ISBLK(inode->i_mode) && !xlo->xlo_encrypt_key_size) { + struct request_queue *backingq; + + backingq = bdev_get_queue(inode->i_bdev); + + max_discard_sectors = backingq->limits.max_write_zeroes_sectors; + granularity = backingq->limits.discard_granularity ?: queue_physical_block_size(backingq); + + /* + * We use punch hole to reclaim the free space used by the + * image a.k.a. discard. However we do not support discard if + * encryption is enabled, because it may give an attacker + * useful information. + */ + } else if (!file->f_op->fallocate || xlo->xlo_encrypt_key_size) { + max_discard_sectors = 0; + granularity = 0; + + } else { + max_discard_sectors = UINT_MAX >> 9; + granularity = inode->i_sb->s_blocksize; + } + + if (max_discard_sectors) { + q->limits.discard_granularity = granularity; + blk_queue_max_discard_sectors(q, max_discard_sectors); + blk_queue_max_write_zeroes_sectors(q, max_discard_sectors); + blk_queue_flag_set(QUEUE_FLAG_DISCARD, q); + } else { + q->limits.discard_granularity = 0; + blk_queue_max_discard_sectors(q, 0); + blk_queue_max_write_zeroes_sectors(q, 0); + blk_queue_flag_clear(QUEUE_FLAG_DISCARD, q); + } + q->limits.discard_alignment = 0; +} + +static void xloop_unprepare_queue(struct xloop_device *xlo) +{ + kthread_flush_worker(&xlo->worker); + kthread_stop(xlo->worker_task); +} + +static int xloop_kthread_worker_fn(void *worker_ptr) +{ + current->flags |= PF_LOCAL_THROTTLE | PF_MEMALLOC_NOIO; + return kthread_worker_fn(worker_ptr); +} + +static int xloop_prepare_queue(struct xloop_device *xlo) +{ + kthread_init_worker(&xlo->worker); + xlo->worker_task = kthread_run(xloop_kthread_worker_fn, &xlo->worker, "xloop%d", xlo->xlo_number); + if (IS_ERR(xlo->worker_task)) + return -ENOMEM; + set_user_nice(xlo->worker_task, MIN_NICE); + return 0; +} + +static void xloop_update_rotational(struct xloop_device *xlo) +{ + struct file *file = xlo->xlo_backing_file; + struct inode *file_inode = file->f_mapping->host; + struct block_device *file_bdev = file_inode->i_sb->s_bdev; + struct request_queue *q = xlo->xlo_queue; + bool nonrot = true; + + /* not all filesystems (e.g. tmpfs) have a sb->s_bdev */ + if (file_bdev) + nonrot = blk_queue_nonrot(bdev_get_queue(file_bdev)); + + if (nonrot) + blk_queue_flag_set(QUEUE_FLAG_NONROT, q); + else + blk_queue_flag_clear(QUEUE_FLAG_NONROT, q); +} + +static int xloop_release_xfer(struct xloop_device *xlo) +{ + int err = 0; + struct xloop_func_table *xfer = xlo->xlo_encryption; + + if (xfer) { + if (xfer->release) + err = xfer->release(xlo); + xlo->transfer = NULL; + xlo->xlo_encryption = NULL; + module_put(xfer->owner); + } + return err; +} + +static int xloop_init_xfer(struct xloop_device *xlo, struct xloop_func_table *xfer, const struct xloop_info64 *i) +{ + int err = 0; + + if (xfer) { + struct module *owner = xfer->owner; + + if (!try_module_get(owner)) + return -EINVAL; + if (xfer->init) + err = xfer->init(xlo, i); + if (err) + module_put(owner); + else + xlo->xlo_encryption = xfer; + } + return err; +} + +/** + * xloop_set_status_from_info - configure device from xloop_info + * @xlo: struct xloop_device to configure + * @info: struct xloop_info64 to configure the device with + * + * Configures the xloop device parameters according to the passed + * in xloop_info64 configuration. + */ +static int xloop_set_status_from_info(struct xloop_device *xlo, const struct xloop_info64 *info) +{ + int err; + struct xloop_func_table *xfer; + kuid_t uid = current_uid(); + + if ((unsigned int)info->xlo_encrypt_key_size > XLO_KEY_SIZE) + return -EINVAL; + + err = xloop_release_xfer(xlo); + if (err) + return err; + + if (info->xlo_encrypt_type) { + unsigned int type = info->xlo_encrypt_type; + + if (type >= MAX_XLO_CRYPT) + return -EINVAL; + xfer = xfer_funcs[type]; + if (xfer == NULL) + return -EINVAL; + } else + xfer = NULL; + + err = xloop_init_xfer(xlo, xfer, info); + if (err) + return err; + + xlo->xlo_offset = info->xlo_offset; + xlo->xlo_sizelimit = info->xlo_sizelimit; + memcpy(xlo->xlo_file_name, info->xlo_file_name, XLO_NAME_SIZE); + memcpy(xlo->xlo_crypt_name, info->xlo_crypt_name, XLO_NAME_SIZE); + xlo->xlo_file_name[XLO_NAME_SIZE - 1] = 0; + xlo->xlo_crypt_name[XLO_NAME_SIZE - 1] = 0; + + if (!xfer) + xfer = &none_funcs; + xlo->transfer = xfer->transfer; + xlo->ioctl = xfer->ioctl; + + xlo->xlo_flags = info->xlo_flags; + + xlo->xlo_encrypt_key_size = info->xlo_encrypt_key_size; + xlo->xlo_init[0] = info->xlo_init[0]; + xlo->xlo_init[1] = info->xlo_init[1]; + if (info->xlo_encrypt_key_size) { + memcpy(xlo->xlo_encrypt_key, info->xlo_encrypt_key, info->xlo_encrypt_key_size); + xlo->xlo_key_owner = uid; + } + + return 0; +} + +static int xloop_configure(struct xloop_device *xlo, fmode_t mode, struct block_device *bdev, + const struct xloop_config *config) +{ + struct file *file; + struct inode *inode; + struct address_space *mapping; + struct block_device *claimed_bdev = NULL; + int error; + loff_t size; + bool partscan; + unsigned short bsize; + + /* This is safe, since we have a reference from open(). */ + __module_get(THIS_MODULE); + + error = -EBADF; + file = fget(config->fd); + if (!file) + goto out; + + /* + * If we don't hold exclusive handle for the device, upgrade to it + * here to avoid changing device under exclusive owner. + */ + if (!(mode & FMODE_EXCL)) { + claimed_bdev = bdev->bd_contains; + error = bd_prepare_to_claim(bdev, claimed_bdev, xloop_configure); + if (error) + goto out_putf; + } + + error = mutex_lock_killable(&xloop_ctl_mutex); + if (error) + goto out_bdev; + + error = -EBUSY; + if (xlo->xlo_state != Xlo_unbound) + goto out_unlock; + + error = xloop_validate_file(file, bdev); + if (error) + goto out_unlock; + + mapping = file->f_mapping; + inode = mapping->host; + + if ((config->info.xlo_flags & ~XLOOP_CONFIGURE_SETTABLE_FLAGS) != 0) { + error = -EINVAL; + goto out_unlock; + } + + if (config->block_size) { + error = xloop_validate_block_size(config->block_size); + if (error) + goto out_unlock; + } + + error = xloop_set_status_from_info(xlo, &config->info); + if (error) + goto out_unlock; + + if (!(file->f_mode & FMODE_WRITE) || !(mode & FMODE_WRITE) || !file->f_op->write_iter) + xlo->xlo_flags |= XLO_FLAGS_READ_ONLY; + + error = xloop_prepare_queue(xlo); + if (error) + goto out_unlock; + + set_device_ro(bdev, (xlo->xlo_flags & XLO_FLAGS_READ_ONLY) != 0); + + xlo->use_dio = xlo->xlo_flags & XLO_FLAGS_DIRECT_IO; + xlo->xlo_device = bdev; + xlo->xlo_backing_file = file; + xlo->old_gfp_mask = mapping_gfp_mask(mapping); + mapping_set_gfp_mask(mapping, xlo->old_gfp_mask & ~(__GFP_IO | __GFP_FS)); + + error = xloop_file_fmt_init(xlo->xlo_fmt, config->info.xlo_file_fmt_type); + if (error) + goto out_unlock; + + if (!(xlo->xlo_flags & XLO_FLAGS_READ_ONLY) && file->f_op->fsync) + blk_queue_write_cache(xlo->xlo_queue, true, false); + + if (config->block_size) + bsize = config->block_size; + else if ((xlo->xlo_backing_file->f_flags & O_DIRECT) && inode->i_sb->s_bdev) + /* In case of direct I/O, match underlying block size */ + bsize = bdev_logical_block_size(inode->i_sb->s_bdev); + else + bsize = 512; + + blk_queue_logical_block_size(xlo->xlo_queue, bsize); + blk_queue_physical_block_size(xlo->xlo_queue, bsize); + blk_queue_io_min(xlo->xlo_queue, bsize); + + xloop_update_rotational(xlo); + xloop_update_dio(xlo); + xloop_sysfs_init(xlo); + + size = get_xloop_size(xlo, file); + xloop_set_size(xlo, size); + + set_blocksize(bdev, S_ISBLK(inode->i_mode) ? block_size(inode->i_bdev) : PAGE_SIZE); + + xlo->xlo_state = Xlo_bound; + if (part_shift) + xlo->xlo_flags |= XLO_FLAGS_PARTSCAN; + partscan = xlo->xlo_flags & XLO_FLAGS_PARTSCAN; + if (partscan) + xlo->xlo_disk->flags &= ~GENHD_FL_NO_PART_SCAN; + + /* Grab the block_device to prevent its destruction after we + * put /dev/xloopXX inode. Later in __xloop_clr_fd() we bdput(bdev). + */ + bdgrab(bdev); + mutex_unlock(&xloop_ctl_mutex); + if (partscan) + xloop_reread_partitions(xlo, bdev); + if (claimed_bdev) + bd_abort_claiming(bdev, claimed_bdev, xloop_configure); + return 0; + +out_unlock: + mutex_unlock(&xloop_ctl_mutex); +out_bdev: + if (claimed_bdev) + bd_abort_claiming(bdev, claimed_bdev, xloop_configure); +out_putf: + fput(file); +out: + /* This is safe: open() is still holding a reference. */ + module_put(THIS_MODULE); + return error; +} + +static int __xloop_clr_fd(struct xloop_device *xlo, bool release) +{ + struct file *filp = NULL; + gfp_t gfp = xlo->old_gfp_mask; + struct block_device *bdev = xlo->xlo_device; + int err = 0; + bool partscan = false; + int xlo_number; + + mutex_lock(&xloop_ctl_mutex); + if (WARN_ON_ONCE(xlo->xlo_state != Xlo_rundown)) { + err = -ENXIO; + goto out_unlock; + } + + filp = xlo->xlo_backing_file; + if (filp == NULL) { + err = -EINVAL; + goto out_unlock; + } + + /* freeze request queue during the transition */ + blk_mq_freeze_queue(xlo->xlo_queue); + + xloop_file_fmt_exit(xlo->xlo_fmt); + + spin_lock_irq(&xlo->xlo_lock); + xlo->xlo_backing_file = NULL; + spin_unlock_irq(&xlo->xlo_lock); + + xloop_release_xfer(xlo); + xlo->transfer = NULL; + xlo->ioctl = NULL; + xlo->xlo_device = NULL; + xlo->xlo_encryption = NULL; + xlo->xlo_offset = 0; + xlo->xlo_sizelimit = 0; + xlo->xlo_encrypt_key_size = 0; + memset(xlo->xlo_encrypt_key, 0, XLO_KEY_SIZE); + memset(xlo->xlo_crypt_name, 0, XLO_NAME_SIZE); + memset(xlo->xlo_file_name, 0, XLO_NAME_SIZE); + blk_queue_logical_block_size(xlo->xlo_queue, 512); + blk_queue_physical_block_size(xlo->xlo_queue, 512); + blk_queue_io_min(xlo->xlo_queue, 512); + if (bdev) { + bdput(bdev); + invalidate_bdev(bdev); + bdev->bd_inode->i_mapping->wb_err = 0; + } + set_capacity(xlo->xlo_disk, 0); + xloop_sysfs_exit(xlo); + if (bdev) { + bd_set_nr_sectors(bdev, 0); + /* let user-space know about this change */ + kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, KOBJ_CHANGE); + } + mapping_set_gfp_mask(filp->f_mapping, gfp); + /* This is safe: open() is still holding a reference. */ + module_put(THIS_MODULE); + blk_mq_unfreeze_queue(xlo->xlo_queue); + + partscan = xlo->xlo_flags & XLO_FLAGS_PARTSCAN && bdev; + xlo_number = xlo->xlo_number; + xloop_unprepare_queue(xlo); +out_unlock: + mutex_unlock(&xloop_ctl_mutex); + if (partscan) { + /* + * bd_mutex has been held already in release path, so don't + * acquire it if this function is called in such case. + * + * If the reread partition isn't from release path, xlo_refcnt + * must be at least one and it can only become zero when the + * current holder is released. + */ + if (!release) + mutex_lock(&bdev->bd_mutex); + err = bdev_disk_changed(bdev, false); + if (!release) + mutex_unlock(&bdev->bd_mutex); + if (err) + dev_warn(xloop_device_to_dev(xlo), "partition scan failed (rc=%d)\n", err); + + /* Device is gone, no point in returning error */ + err = 0; + } + + /* + * xlo->xlo_state is set to Xlo_unbound here after above partscan has + * finished. + * + * There cannot be anybody else entering __xloop_clr_fd() as + * xlo->xlo_backing_file is already cleared and Xlo_rundown state + * protects us from all the other places trying to change the 'xlo' + * device. + */ + mutex_lock(&xloop_ctl_mutex); + xlo->xlo_flags = 0; + if (!part_shift) + xlo->xlo_disk->flags |= GENHD_FL_NO_PART_SCAN; + xlo->xlo_state = Xlo_unbound; + mutex_unlock(&xloop_ctl_mutex); + + /* + * Need not hold xloop_ctl_mutex to fput backing file. + * Calling fput holding xloop_ctl_mutex triggers a circular + * lock dependency possibility warning as fput can take + * bd_mutex which is usually taken before xloop_ctl_mutex. + */ + if (filp) + fput(filp); + return err; +} + +static int xloop_clr_fd(struct xloop_device *xlo) +{ + int err; + + err = mutex_lock_killable(&xloop_ctl_mutex); + if (err) + return err; + if (xlo->xlo_state != Xlo_bound) { + mutex_unlock(&xloop_ctl_mutex); + return -ENXIO; + } + /* + * If we've explicitly asked to tear down the xloop device, + * and it has an elevated reference count, set it for auto-teardown when + * the last reference goes away. This stops $!~#$@ udev from + * preventing teardown because it decided that it needs to run blkid on + * the xloopback device whenever they appear. xfstests is notorious for + * failing tests because blkid via udev races with a losetup + * <dev>/do something like mkfs/losetup -d <dev> causing the losetup -d + * command to fail with EBUSY. + */ + if (atomic_read(&xlo->xlo_refcnt) > 1) { + xlo->xlo_flags |= XLO_FLAGS_AUTOCLEAR; + mutex_unlock(&xloop_ctl_mutex); + return 0; + } + xlo->xlo_state = Xlo_rundown; + mutex_unlock(&xloop_ctl_mutex); + + return __xloop_clr_fd(xlo, false); +} + +static int xloop_set_status(struct xloop_device *xlo, const struct xloop_info64 *info) +{ + int err; + struct block_device *bdev; + kuid_t uid = current_uid(); + int prev_xlo_flags; + bool partscan = false; + bool size_changed = false; + + err = mutex_lock_killable(&xloop_ctl_mutex); + if (err) + return err; + if (xlo->xlo_encrypt_key_size && !uid_eq(xlo->xlo_key_owner, uid) && !capable(CAP_SYS_ADMIN)) { + err = -EPERM; + goto out_unlock; + } + if (xlo->xlo_state != Xlo_bound) { + err = -ENXIO; + goto out_unlock; + } + + if (xlo->xlo_offset != info->xlo_offset || xlo->xlo_sizelimit != info->xlo_sizelimit) { + size_changed = true; + sync_blockdev(xlo->xlo_device); + invalidate_bdev(xlo->xlo_device); + } + + /* I/O need to be drained during transfer transition */ + blk_mq_freeze_queue(xlo->xlo_queue); + + if (size_changed && xlo->xlo_device->bd_inode->i_mapping->nrpages) { + /* If any pages were dirtied after invalidate_bdev(), try again */ + err = -EAGAIN; + dev_warn(xloop_device_to_dev(xlo), + "xloop device has still dirty pages (nrpages=%lu)\n", + xlo->xlo_device->bd_inode->i_mapping->nrpages); + goto out_unfreeze; + } + + prev_xlo_flags = xlo->xlo_flags; + + err = xloop_set_status_from_info(xlo, info); + if (err) + goto out_unfreeze; + + /* Mask out flags that can't be set using XLOOP_SET_STATUS. */ + xlo->xlo_flags &= XLOOP_SET_STATUS_SETTABLE_FLAGS; + /* For those flags, use the previous values instead */ + xlo->xlo_flags |= prev_xlo_flags & ~XLOOP_SET_STATUS_SETTABLE_FLAGS; + /* For flags that can't be cleared, use previous values too */ + xlo->xlo_flags |= prev_xlo_flags & ~XLOOP_SET_STATUS_CLEARABLE_FLAGS; + + if (xlo->xlo_fmt->file_fmt_type != info->xlo_file_fmt_type) { + /* xloop file format has changed, so change file format driver */ + err = xloop_file_fmt_change(xlo->xlo_fmt, info->xlo_file_fmt_type); + if (err) + goto out_unfreeze; + + /* After change of the file format, recalculate the capacity of the xloop device. */ + size_changed = true; + } + + if (size_changed) { + loff_t new_size = get_xloop_size(xlo, xlo->xlo_backing_file); + + xloop_set_size(xlo, new_size); + } + + xloop_config_discard(xlo); + + /* update dio if xlo_offset or transfer is changed */ + __xloop_update_dio(xlo, xlo->use_dio); + +out_unfreeze: + blk_mq_unfreeze_queue(xlo->xlo_queue); + + if (!err && (xlo->xlo_flags & XLO_FLAGS_PARTSCAN) && !(prev_xlo_flags & XLO_FLAGS_PARTSCAN)) { + xlo->xlo_disk->flags &= ~GENHD_FL_NO_PART_SCAN; + bdev = xlo->xlo_device; + partscan = true; + } +out_unlock: + mutex_unlock(&xloop_ctl_mutex); + if (partscan) + xloop_reread_partitions(xlo, bdev); + + return err; +} + +static int xloop_get_status(struct xloop_device *xlo, struct xloop_info64 *info) +{ + struct path path; + struct kstat stat; + int ret; + + ret = mutex_lock_killable(&xloop_ctl_mutex); + if (ret) + return ret; + if (xlo->xlo_state != Xlo_bound) { + mutex_unlock(&xloop_ctl_mutex); + return -ENXIO; + } + + memset(info, 0, sizeof(*info)); + info->xlo_number = xlo->xlo_number; + info->xlo_offset = xlo->xlo_offset; + info->xlo_sizelimit = xlo->xlo_sizelimit; + info->xlo_flags = xlo->xlo_flags; + memcpy(info->xlo_file_name, xlo->xlo_file_name, XLO_NAME_SIZE); + memcpy(info->xlo_crypt_name, xlo->xlo_crypt_name, XLO_NAME_SIZE); + info->xlo_encrypt_type = xlo->xlo_encryption ? xlo->xlo_encryption->number : 0; + if (xlo->xlo_encrypt_key_size && capable(CAP_SYS_ADMIN)) { + info->xlo_encrypt_key_size = xlo->xlo_encrypt_key_size; + memcpy(info->xlo_encrypt_key, xlo->xlo_encrypt_key, xlo->xlo_encrypt_key_size); + } + + /* Drop xloop_ctl_mutex while we call into the filesystem. */ + path = xlo->xlo_backing_file->f_path; + path_get(&path); + mutex_unlock(&xloop_ctl_mutex); + ret = vfs_getattr(&path, &stat, STATX_INO, AT_STATX_SYNC_AS_STAT); + if (!ret) { + info->xlo_device = huge_encode_dev(stat.dev); + info->xlo_inode = stat.ino; + info->xlo_rdevice = huge_encode_dev(stat.rdev); + } + path_put(&path); + return ret; +} + +static void xloop_info64_from_old(const struct xloop_info *info, struct xloop_info64 *info64) +{ + memset(info64, 0, sizeof(*info64)); + info64->xlo_number = info->xlo_number; + info64->xlo_device = info->xlo_device; + info64->xlo_inode = info->xlo_inode; + info64->xlo_rdevice = info->xlo_rdevice; + info64->xlo_offset = info->xlo_offset; + info64->xlo_sizelimit = 0; + info64->xlo_encrypt_type = info->xlo_encrypt_type; + info64->xlo_encrypt_key_size = info->xlo_encrypt_key_size; + info64->xlo_flags = info->xlo_flags; + info64->xlo_init[0] = info->xlo_init[0]; + info64->xlo_init[1] = info->xlo_init[1]; + info64->xlo_file_fmt_type = info->xlo_file_fmt_type; + if (info->xlo_encrypt_type == XLO_CRYPT_CRYPTOAPI) + memcpy(info64->xlo_crypt_name, info->xlo_name, XLO_NAME_SIZE); + else + memcpy(info64->xlo_file_name, info->xlo_name, XLO_NAME_SIZE); + memcpy(info64->xlo_encrypt_key, info->xlo_encrypt_key, XLO_KEY_SIZE); +} + +static int xloop_info64_to_old(const struct xloop_info64 *info64, struct xloop_info *info) +{ + memset(info, 0, sizeof(*info)); + info->xlo_number = info64->xlo_number; + info->xlo_device = info64->xlo_device; + info->xlo_inode = info64->xlo_inode; + info->xlo_rdevice = info64->xlo_rdevice; + info->xlo_offset = info64->xlo_offset; + info->xlo_encrypt_type = info64->xlo_encrypt_type; + info->xlo_encrypt_key_size = info64->xlo_encrypt_key_size; + info->xlo_flags = info64->xlo_flags; + info->xlo_init[0] = info64->xlo_init[0]; + info->xlo_init[1] = info64->xlo_init[1]; + info->xlo_file_fmt_type = info64->xlo_file_fmt_type; + if (info->xlo_encrypt_type == XLO_CRYPT_CRYPTOAPI) + memcpy(info->xlo_name, info64->xlo_crypt_name, XLO_NAME_SIZE); + else + memcpy(info->xlo_name, info64->xlo_file_name, XLO_NAME_SIZE); + memcpy(info->xlo_encrypt_key, info64->xlo_encrypt_key, XLO_KEY_SIZE); + + /* error in case values were truncated */ + if (info->xlo_device != info64->xlo_device || info->xlo_rdevice != info64->xlo_rdevice || + info->xlo_inode != info64->xlo_inode || info->xlo_offset != info64->xlo_offset) + return -EOVERFLOW; + + return 0; +} + +static int xloop_set_status_old(struct xloop_device *xlo, const struct xloop_info __user *arg) +{ + struct xloop_info info; + struct xloop_info64 info64; + + if (copy_from_user(&info, arg, sizeof(struct xloop_info))) + return -EFAULT; + xloop_info64_from_old(&info, &info64); + return xloop_set_status(xlo, &info64); +} + +static int xloop_set_status64(struct xloop_device *xlo, const struct xloop_info64 __user *arg) +{ + struct xloop_info64 info64; + + if (copy_from_user(&info64, arg, sizeof(struct xloop_info64))) + return -EFAULT; + return xloop_set_status(xlo, &info64); +} + +static int xloop_get_status_old(struct xloop_device *xlo, struct xloop_info __user *arg) +{ + struct xloop_info info; + struct xloop_info64 info64; + int err; + + if (!arg) + return -EINVAL; + err = xloop_get_status(xlo, &info64); + if (!err) + err = xloop_info64_to_old(&info64, &info); + if (!err && copy_to_user(arg, &info, sizeof(info))) + err = -EFAULT; + + return err; +} + +static int xloop_get_status64(struct xloop_device *xlo, struct xloop_info64 __user *arg) +{ + struct xloop_info64 info64; + int err; + + if (!arg) + return -EINVAL; + err = xloop_get_status(xlo, &info64); + if (!err && copy_to_user(arg, &info64, sizeof(info64))) + err = -EFAULT; + + return err; +} + +static int xloop_set_capacity(struct xloop_device *xlo) +{ + loff_t size; + + if (unlikely(xlo->xlo_state != Xlo_bound)) + return -ENXIO; + + size = get_xloop_size(xlo, xlo->xlo_backing_file); + xloop_set_size(xlo, size); + + return 0; +} + +static int xloop_set_dio(struct xloop_device *xlo, unsigned long arg) +{ + int error = -ENXIO; + + if (xlo->xlo_state != Xlo_bound) + goto out; + + __xloop_update_dio(xlo, !!arg); + if (xlo->use_dio == !!arg) + return 0; + error = -EINVAL; +out: + return error; +} + +static int xloop_set_block_size(struct xloop_device *xlo, unsigned long arg) +{ + int err = 0; + + if (xlo->xlo_state != Xlo_bound) + return -ENXIO; + + err = xloop_validate_block_size(arg); + if (err) + return err; + + if (xlo->xlo_queue->limits.logical_block_size == arg) + return 0; + + sync_blockdev(xlo->xlo_device); + invalidate_bdev(xlo->xlo_device); + + blk_mq_freeze_queue(xlo->xlo_queue); + + /* invalidate_bdev should have truncated all the pages */ + if (xlo->xlo_device->bd_inode->i_mapping->nrpages) { + err = -EAGAIN; + dev_warn(xloop_device_to_dev(xlo), + "xloop device has still dirty pages (nrpages=%lu)\n", + xlo->xlo_device->bd_inode->i_mapping->nrpages); + goto out_unfreeze; + } + + blk_queue_logical_block_size(xlo->xlo_queue, arg); + blk_queue_physical_block_size(xlo->xlo_queue, arg); + blk_queue_io_min(xlo->xlo_queue, arg); + xloop_update_dio(xlo); +out_unfreeze: + blk_mq_unfreeze_queue(xlo->xlo_queue); + + return err; +} + +static int xlo_simple_ioctl(struct xloop_device *xlo, unsigned int cmd, unsigned long arg) +{ + int err; + + err = mutex_lock_killable(&xloop_ctl_mutex); + if (err) + return err; + switch (cmd) { + case XLOOP_SET_CAPACITY: + err = xloop_set_capacity(xlo); + break; + case XLOOP_SET_DIRECT_IO: + err = xloop_set_dio(xlo, arg); + break; + case XLOOP_SET_BLOCK_SIZE: + err = xloop_set_block_size(xlo, arg); + break; + default: + err = xlo->ioctl ? xlo->ioctl(xlo, cmd, arg) : -EINVAL; + } + mutex_unlock(&xloop_ctl_mutex); + return err; +} + +static int xlo_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd, unsigned long arg) +{ + struct xloop_device *xlo = bdev->bd_disk->private_data; + void __user *argp = (void __user *)arg; + int err; + + switch (cmd) { + case XLOOP_SET_FD: { + /* + * Legacy case - pass in a zeroed out struct xloop_config with + * only the file descriptor set , which corresponds with the + * default parameters we'd have used otherwise. + */ + struct xloop_config config; + + memset(&config, 0, sizeof(config)); + config.fd = arg; + + return xloop_configure(xlo, mode, bdev, &config); + } + case XLOOP_CONFIGURE: { + struct xloop_config config; + + if (copy_from_user(&config, argp, sizeof(config))) + return -EFAULT; + + return xloop_configure(xlo, mode, bdev, &config); + } + case XLOOP_CHANGE_FD: + return xloop_change_fd(xlo, bdev, arg); + case XLOOP_CLR_FD: + return xloop_clr_fd(xlo); + case XLOOP_SET_STATUS: + err = -EPERM; + if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN)) + err = xloop_set_status_old(xlo, argp); + break; + case XLOOP_GET_STATUS: + return xloop_get_status_old(xlo, argp); + case XLOOP_SET_STATUS64: + err = -EPERM; + if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN)) + err = xloop_set_status64(xlo, argp); + break; + case XLOOP_GET_STATUS64: + return xloop_get_status64(xlo, argp); + case XLOOP_SET_CAPACITY: + case XLOOP_SET_DIRECT_IO: + case XLOOP_SET_BLOCK_SIZE: + if (!(mode & FMODE_WRITE) && !capable(CAP_SYS_ADMIN)) + return -EPERM; + fallthrough; + default: + err = xlo_simple_ioctl(xlo, cmd, arg); + break; + } + + return err; +} + +#ifdef CONFIG_COMPAT +struct compat_xloop_info { + compat_int_t xlo_number; /* ioctl r/o */ + compat_dev_t xlo_device; /* ioctl r/o */ + compat_ulong_t xlo_inode; /* ioctl r/o */ + compat_dev_t xlo_rdevice; /* ioctl r/o */ + compat_int_t xlo_offset; + compat_int_t xlo_encrypt_type; + compat_int_t xlo_encrypt_key_size; /* ioctl w/o */ + compat_int_t xlo_flags; /* ioctl r/o */ + char xlo_name[XLO_NAME_SIZE]; + unsigned char xlo_encrypt_key[XLO_KEY_SIZE]; /* ioctl w/o */ + compat_ulong_t xlo_init[2]; + char reserved[4]; + compat_int_t xlo_file_fmt_type; +}; + +/* + * Transfer 32-bit compatibility structure in userspace to 64-bit xloop info + * - noinlined to reduce stack space usage in main part of driver + */ +static noinline int xloop_info64_from_compat(const struct compat_xloop_info __user *arg, struct xloop_info64 *info64) +{ + struct compat_xloop_info info; + + if (copy_from_user(&info, arg, sizeof(info))) + return -EFAULT; + + memset(info64, 0, sizeof(*info64)); + info64->xlo_number = info.xlo_number; + info64->xlo_device = info.xlo_device; + info64->xlo_inode = info.xlo_inode; + info64->xlo_rdevice = info.xlo_rdevice; + info64->xlo_offset = info.xlo_offset; + info64->xlo_sizelimit = 0; + info64->xlo_encrypt_type = info.xlo_encrypt_type; + info64->xlo_encrypt_key_size = info.xlo_encrypt_key_size; + info64->xlo_flags = info.xlo_flags; + info64->xlo_init[0] = info.xlo_init[0]; + info64->xlo_init[1] = info.xlo_init[1]; + info64->xlo_file_fmt_type = info.xlo_file_fmt_type; + if (info.xlo_encrypt_type == XLO_CRYPT_CRYPTOAPI) + memcpy(info64->xlo_crypt_name, info.xlo_name, XLO_NAME_SIZE); + else + memcpy(info64->xlo_file_name, info.xlo_name, XLO_NAME_SIZE); + memcpy(info64->xlo_encrypt_key, info.xlo_encrypt_key, XLO_KEY_SIZE); + return 0; +} + +/* + * Transfer 64-bit xloop info to 32-bit compatibility structure in userspace + * - noinlined to reduce stack space usage in main part of driver + */ +static noinline int xloop_info64_to_compat(const struct xloop_info64 *info64, struct compat_xloop_info __user *arg) +{ + struct compat_xloop_info info; + + memset(&info, 0, sizeof(info)); + info.xlo_number = info64->xlo_number; + info.xlo_device = info64->xlo_device; + info.xlo_inode = info64->xlo_inode; + info.xlo_rdevice = info64->xlo_rdevice; + info.xlo_offset = info64->xlo_offset; + info.xlo_encrypt_type = info64->xlo_encrypt_type; + info.xlo_encrypt_key_size = info64->xlo_encrypt_key_size; + info.xlo_flags = info64->xlo_flags; + info.xlo_init[0] = info64->xlo_init[0]; + info.xlo_init[1] = info64->xlo_init[1]; + info.xlo_file_fmt_type = info64->xlo_file_fmt_type; + if (info.xlo_encrypt_type == XLO_CRYPT_CRYPTOAPI) + memcpy(info.xlo_name, info64->xlo_crypt_name, XLO_NAME_SIZE); + else + memcpy(info.xlo_name, info64->xlo_file_name, XLO_NAME_SIZE); + memcpy(info.xlo_encrypt_key, info64->xlo_encrypt_key, XLO_KEY_SIZE); + + /* error in case values were truncated */ + if (info.xlo_device != info64->xlo_device || info.xlo_rdevice != info64->xlo_rdevice || + info.xlo_inode != info64->xlo_inode || info.xlo_offset != info64->xlo_offset || + info.xlo_init[0] != info64->xlo_init[0] || info.xlo_init[1] != info64->xlo_init[1] || + info.xlo_file_fmt_type != info64->xlo_file_fmt_type) + return -EOVERFLOW; + + if (copy_to_user(arg, &info, sizeof(info))) + return -EFAULT; + return 0; +} + +static int xloop_set_status_compat(struct xloop_device *xlo, const struct compat_xloop_info __user *arg) +{ + struct xloop_info64 info64; + int ret; + + ret = xloop_info64_from_compat(arg, &info64); + if (ret < 0) + return ret; + return xloop_set_status(xlo, &info64); +} + +static int xloop_get_status_compat(struct xloop_device *xlo, struct compat_xloop_info __user *arg) +{ + struct xloop_info64 info64; + int err; + + if (!arg) + return -EINVAL; + err = xloop_get_status(xlo, &info64); + if (!err) + err = xloop_info64_to_compat(&info64, arg); + return err; +} + +static int xlo_compat_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd, unsigned long arg) +{ + struct xloop_device *xlo = bdev->bd_disk->private_data; + int err; + + switch (cmd) { + case XLOOP_SET_STATUS: + err = xloop_set_status_compat(xlo, (const struct compat_xloop_info __user *)arg); + break; + case XLOOP_GET_STATUS: + err = xloop_get_status_compat(xlo, (struct compat_xloop_info __user *)arg); + break; + case XLOOP_SET_CAPACITY: + case XLOOP_CLR_FD: + case XLOOP_GET_STATUS64: + case XLOOP_SET_STATUS64: + case XLOOP_CONFIGURE: + arg = (unsigned long)compat_ptr(arg); + fallthrough; + case XLOOP_SET_FD: + case XLOOP_CHANGE_FD: + case XLOOP_SET_BLOCK_SIZE: + case XLOOP_SET_DIRECT_IO: + err = xlo_ioctl(bdev, mode, cmd, arg); + break; + default: + err = -ENOIOCTLCMD; + break; + } + return err; +} +#endif + +static int xlo_open(struct block_device *bdev, fmode_t mode) +{ + struct xloop_device *xlo; + int err; + + err = mutex_lock_killable(&xloop_ctl_mutex); + if (err) + return err; + xlo = bdev->bd_disk->private_data; + if (!xlo) { + err = -ENXIO; + goto out; + } + + atomic_inc(&xlo->xlo_refcnt); +out: + mutex_unlock(&xloop_ctl_mutex); + return err; +} + +static void xlo_release(struct gendisk *disk, fmode_t mode) +{ + struct xloop_device *xlo; + + mutex_lock(&xloop_ctl_mutex); + xlo = disk->private_data; + if (atomic_dec_return(&xlo->xlo_refcnt)) + goto out_unlock; + + if (xlo->xlo_flags & XLO_FLAGS_AUTOCLEAR) { + if (xlo->xlo_state != Xlo_bound) + goto out_unlock; + xlo->xlo_state = Xlo_rundown; + mutex_unlock(&xloop_ctl_mutex); + /* + * In autoclear mode, stop the xloop thread + * and remove configuration after last close. + */ + __xloop_clr_fd(xlo, true); + return; + } else if (xlo->xlo_state == Xlo_bound) { + /* + * Otherwise keep thread (if running) and config, + * but flush possible ongoing bios in thread. + */ + blk_mq_freeze_queue(xlo->xlo_queue); + blk_mq_unfreeze_queue(xlo->xlo_queue); + } + +out_unlock: + mutex_unlock(&xloop_ctl_mutex); +} + +static const struct block_device_operations xlo_fops = { + .owner = THIS_MODULE, + .open = xlo_open, + .release = xlo_release, + .ioctl = xlo_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = xlo_compat_ioctl, +#endif +}; + +/* + * And now the modules code and kernel interface. + */ +static int max_xloop; +module_param(max_xloop, int, 0444); +MODULE_PARM_DESC(max_xloop, "Maximum number of xloop devices"); +module_param(max_part, int, 0444); +MODULE_PARM_DESC(max_part, "Maximum number of partitions per xloop device"); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Manuel Bentele <development@manuel-bentele.de>"); +MODULE_VERSION(XLOOP_VERSION); +MODULE_ALIAS_BLOCKDEV_MAJOR(XLOOP_MAJOR); + +int xloop_register_transfer(struct xloop_func_table *funcs) +{ + unsigned int n = funcs->number; + + if (n >= MAX_XLO_CRYPT || xfer_funcs[n]) + return -EINVAL; + xfer_funcs[n] = funcs; + return 0; +} +EXPORT_SYMBOL(xloop_register_transfer); + +static int unregister_transfer_cb(int id, void *ptr, void *data) +{ + struct xloop_device *xlo = ptr; + struct xloop_func_table *xfer = data; + + mutex_lock(&xloop_ctl_mutex); + if (xlo->xlo_encryption == xfer) + xloop_release_xfer(xlo); + mutex_unlock(&xloop_ctl_mutex); + return 0; +} + +int xloop_unregister_transfer(int number) +{ + unsigned int n = number; + struct xloop_func_table *xfer; + + xfer = xfer_funcs[n]; + + if (n == 0 || n >= MAX_XLO_CRYPT || xfer == NULL) + return -EINVAL; + + xfer_funcs[n] = NULL; + idr_for_each(&xloop_index_idr, &unregister_transfer_cb, xfer); + return 0; +} +EXPORT_SYMBOL(xloop_unregister_transfer); + +static blk_status_t xloop_queue_rq(struct blk_mq_hw_ctx *hctx, const struct blk_mq_queue_data *bd) +{ + struct request *rq = bd->rq; + struct xloop_cmd *cmd = blk_mq_rq_to_pdu(rq); + struct xloop_device *xlo = rq->q->queuedata; + + blk_mq_start_request(rq); + + if (xlo->xlo_state != Xlo_bound) + return BLK_STS_IOERR; + + switch (req_op(rq)) { + case REQ_OP_FLUSH: + case REQ_OP_DISCARD: + case REQ_OP_WRITE_ZEROES: + cmd->use_aio = false; + break; + default: + cmd->use_aio = xlo->use_dio; + break; + } + + /* always use the first bio's css */ +#ifdef CONFIG_BLK_CGROUP + if (cmd->use_aio && rq->bio && rq->bio->bi_blkg) { + cmd->css = &bio_blkcg(rq->bio)->css; + css_get(cmd->css); + } else +#endif + cmd->css = NULL; + kthread_queue_work(&xlo->worker, &cmd->work); + + return BLK_STS_OK; +} + +static void xloop_handle_cmd(struct xloop_cmd *cmd) +{ + struct request *rq = blk_mq_rq_from_pdu(cmd); + const bool write = op_is_write(req_op(rq)); + struct xloop_device *xlo = rq->q->queuedata; + int ret = 0; + + if (write && (xlo->xlo_flags & XLO_FLAGS_READ_ONLY)) { + ret = -EIO; + goto failed; + } + + ret = do_req_filebacked(xlo, rq); +failed: + /* complete non-aio request */ + if (!cmd->use_aio || ret) { + if (ret == -EOPNOTSUPP) + cmd->ret = ret; + else + cmd->ret = ret ? -EIO : 0; + if (likely(!blk_should_fake_timeout(rq->q))) + blk_mq_complete_request(rq); + } +} + +static void xloop_queue_work(struct kthread_work *work) +{ + struct xloop_cmd *cmd = container_of(work, struct xloop_cmd, work); + + xloop_handle_cmd(cmd); +} + +static int xloop_init_request(struct blk_mq_tag_set *set, struct request *rq, unsigned int hctx_idx, + unsigned int numa_node) +{ + struct xloop_cmd *cmd = blk_mq_rq_to_pdu(rq); + + kthread_init_work(&cmd->work, xloop_queue_work); + return 0; +} + +static const struct blk_mq_ops xloop_mq_ops = { + .queue_rq = xloop_queue_rq, + .init_request = xloop_init_request, + .complete = xlo_complete_rq, +}; + +static struct dentry *xloop_dbgfs_dir; + +static int xloop_add(struct xloop_device **l, int i) +{ + struct xloop_device *xlo; + struct gendisk *disk; + int err; + + err = -ENOMEM; + xlo = kzalloc(sizeof(*xlo), GFP_KERNEL); + if (!xlo) + goto out; + + xlo->xlo_state = Xlo_unbound; + + /* allocate id, if @id >= 0, we're requesting that specific id */ + if (i >= 0) { + err = idr_alloc(&xloop_index_idr, xlo, i, i + 1, GFP_KERNEL); + if (err == -ENOSPC) + err = -EEXIST; + } else { + err = idr_alloc(&xloop_index_idr, xlo, 0, 0, GFP_KERNEL); + } + if (err < 0) + goto out_free_dev; + i = err; + + err = -ENOMEM; + xlo->tag_set.ops = &xloop_mq_ops; + xlo->tag_set.nr_hw_queues = 1; + xlo->tag_set.queue_depth = 128; + xlo->tag_set.numa_node = NUMA_NO_NODE; + xlo->tag_set.cmd_size = sizeof(struct xloop_cmd); + xlo->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_STACKING; + xlo->tag_set.driver_data = xlo; + + err = blk_mq_alloc_tag_set(&xlo->tag_set); + if (err) + goto out_free_idr; + + xlo->xlo_queue = blk_mq_init_queue(&xlo->tag_set); + if (IS_ERR(xlo->xlo_queue)) { + err = PTR_ERR(xlo->xlo_queue); + goto out_cleanup_tags; + } + xlo->xlo_queue->queuedata = xlo; + + blk_queue_max_hw_sectors(xlo->xlo_queue, BLK_DEF_MAX_SECTORS); + + /* + * By default, we do buffer IO, so it doesn't make sense to enable + * merge because the I/O submitted to backing file is handled page by + * page. For directio mode, merge does help to dispatch bigger request + * to underlayer disk. We will enable merge once directio is enabled. + */ + blk_queue_flag_set(QUEUE_FLAG_NOMERGES, xlo->xlo_queue); + + err = -ENOMEM; + xlo->xlo_fmt = xloop_file_fmt_alloc(); + if (!xlo->xlo_fmt) + goto out_free_queue; + + xloop_file_fmt_set_xlo(xlo->xlo_fmt, xlo); + + err = -ENOMEM; + disk = xlo->xlo_disk = alloc_disk(1 << part_shift); + if (!disk) + goto out_free_file_fmt; + + /* + * Disable partition scanning by default. The in-kernel partition + * scanning can be requested individually per-device during its + * setup. Userspace can always add and remove partitions from all + * devices. The needed partition minors are allocated from the + * extended minor space, the main xloop device numbers will continue + * to match the xloop minors, regardless of the number of partitions + * used. + * + * If max_part is given, partition scanning is globally enabled for + * all xloop devices. The minors for the main xloop devices will be + * multiples of max_part. + * + * Note: Global-for-all-devices, set-only-at-init, read-only module + * parameteters like 'max_xloop' and 'max_part' make things needlessly + * complicated, are too static, inflexible and may surprise + * userspace tools. Parameters like this in general should be avoided. + */ + if (!part_shift) + disk->flags |= GENHD_FL_NO_PART_SCAN; + disk->flags |= GENHD_FL_EXT_DEVT; + atomic_set(&xlo->xlo_refcnt, 0); + xlo->xlo_number = i; + spin_lock_init(&xlo->xlo_lock); + disk->major = XLOOP_MAJOR; + disk->first_minor = i << part_shift; + disk->fops = &xlo_fops; + disk->private_data = xlo; + disk->queue = xlo->xlo_queue; + sprintf(disk->disk_name, "xloop%d", i); + add_disk(disk); + *l = xlo; + + /* + * initialize debugfs entries + * + * create for each loop device a debugfs directory under 'loop' if + * the 'block' directory exists, otherwise create the loop directory in + * the root directory + */ +#ifdef CONFIG_DEBUG_FS + xlo->xlo_dbgfs_dir = debugfs_create_dir(disk->disk_name, xloop_dbgfs_dir); + + if (IS_ERR_OR_NULL(xlo->xlo_dbgfs_dir)) { + err = -ENODEV; + xlo->xlo_dbgfs_dir = NULL; + goto out_free_file_fmt; + } +#endif + + return xlo->xlo_number; + +out_free_file_fmt: + xloop_file_fmt_free(xlo->xlo_fmt); +out_free_queue: + blk_cleanup_queue(xlo->xlo_queue); +out_cleanup_tags: + blk_mq_free_tag_set(&xlo->tag_set); +out_free_idr: + idr_remove(&xloop_index_idr, i); +out_free_dev: + kfree(xlo); +out: + return err; +} + +static void xloop_remove(struct xloop_device *xlo) +{ + xloop_file_fmt_free(xlo->xlo_fmt); + debugfs_remove(xlo->xlo_dbgfs_dir); + del_gendisk(xlo->xlo_disk); + blk_cleanup_queue(xlo->xlo_queue); + blk_mq_free_tag_set(&xlo->tag_set); + put_disk(xlo->xlo_disk); + kfree(xlo); +} + +static int find_free_cb(int id, void *ptr, void *data) +{ + struct xloop_device *xlo = ptr; + struct xloop_device **l = data; + + if (xlo->xlo_state == Xlo_unbound) { + *l = xlo; + return 1; + } + return 0; +} + +static int xloop_lookup(struct xloop_device **l, int i) +{ + struct xloop_device *xlo; + int ret = -ENODEV; + + if (i < 0) { + int err; + + err = idr_for_each(&xloop_index_idr, &find_free_cb, &xlo); + if (err == 1) { + *l = xlo; + ret = xlo->xlo_number; + } + goto out; + } + + /* lookup and return a specific i */ + xlo = idr_find(&xloop_index_idr, i); + if (xlo) { + *l = xlo; + ret = xlo->xlo_number; + } +out: + return ret; +} + +static void xloop_probe(dev_t dev) +{ + struct xloop_device *xlo; + int err; + + mutex_lock(&xloop_ctl_mutex); + err = xloop_lookup(&xlo, MINOR(dev) >> part_shift); + if (err < 0) + err = xloop_add(&xlo, MINOR(dev) >> part_shift); + mutex_unlock(&xloop_ctl_mutex); +} + +static long xloop_control_ioctl(struct file *file, unsigned int cmd, unsigned long parm) +{ + struct xloop_device *xlo; + int ret; + + ret = mutex_lock_killable(&xloop_ctl_mutex); + if (ret) + return ret; + + ret = -EINVAL; + switch (cmd) { + case XLOOP_CTL_ADD: + ret = xloop_lookup(&xlo, parm); + if (ret >= 0) { + ret = -EEXIST; + break; + } + ret = xloop_add(&xlo, parm); + break; + case XLOOP_CTL_REMOVE: + ret = xloop_lookup(&xlo, parm); + if (ret < 0) + break; + if (xlo->xlo_state != Xlo_unbound) { + ret = -EBUSY; + break; + } + if (atomic_read(&xlo->xlo_refcnt) > 0) { + ret = -EBUSY; + break; + } + xlo->xlo_disk->private_data = NULL; + idr_remove(&xloop_index_idr, xlo->xlo_number); + xloop_remove(xlo); + break; + case XLOOP_CTL_GET_FREE: + ret = xloop_lookup(&xlo, -1); + if (ret >= 0) + break; + ret = xloop_add(&xlo, -1); + } + mutex_unlock(&xloop_ctl_mutex); + + return ret; +} + +static const struct file_operations xloop_ctl_fops = { + .open = nonseekable_open, + .unlocked_ioctl = xloop_control_ioctl, + .compat_ioctl = xloop_control_ioctl, + .owner = THIS_MODULE, + .llseek = noop_llseek, +}; + +static struct miscdevice xloop_misc = { + .minor = XLOOP_CTRL_MINOR, + .name = "xloop-control", + .fops = &xloop_ctl_fops, +}; + +MODULE_ALIAS_MISCDEV(XLOOP_CTRL_MINOR); +MODULE_ALIAS("devname:xloop-control"); + +static int __init xloop_init(void) +{ + int i, nr; + unsigned long range; + struct xloop_device *xlo; + int err; + + part_shift = 0; + if (max_part > 0) { + part_shift = fls(max_part); + + /* + * Adjust max_part according to part_shift as it is exported + * to user space so that user can decide correct minor number + * if [s]he want to create more devices. + * + * Note that -1 is required because partition 0 is reserved + * for the whole disk. + */ + max_part = (1UL << part_shift) - 1; + } + + if ((1UL << part_shift) > DISK_MAX_PARTS) { + err = -EINVAL; + goto err_out; + } + + if (max_xloop > 1UL << (MINORBITS - part_shift)) { + err = -EINVAL; + goto err_out; + } + + /* + * If max_xloop is specified, create that many devices upfront. + * This also becomes a hard limit. If max_xloop is not specified, + * create CONFIG_BLK_DEV_XLOOP_MIN_COUNT xloop devices at module + * init time. xloop devices can be requested on-demand with the + * /dev/xloop-control interface, or be instantiated by accessing + * a 'dead' device node. + */ + if (max_xloop) { + nr = CONFIG_BLK_DEV_XLOOP_MIN_COUNT; + range = 1UL << MINORBITS; + } + + err = misc_register(&xloop_misc); + if (err < 0) + goto err_out; + + if (register_blkdev(XLOOP_MAJOR, "xloop")) { + err = -EIO; + goto misc_out; + } + +#ifdef CONFIG_DEBUG_FS + xloop_dbgfs_dir = debugfs_create_dir("xloop", NULL); + if (IS_ERR_OR_NULL(xloop_dbgfs_dir)) { + err = -ENODEV; + goto misc_out; + } +#endif + + if (__register_blkdev(XLOOP_MAJOR, "xloop", xloop_probe)) { + err = -EIO; + goto misc_out; + } + + /* pre-create number of devices given by config or max_xloop */ + mutex_lock(&xloop_ctl_mutex); + for (i = 0; i < nr; i++) + xloop_add(&xlo, i); + mutex_unlock(&xloop_ctl_mutex); + + pr_info("module in version %s loaded\n", XLOOP_VERSION); + return 0; + +misc_out: + misc_deregister(&xloop_misc); +err_out: + return err; +} + +static void __exit xloop_exit(void) +{ + struct xloop_device *xlo; + int id; + + unregister_blkdev(XLOOP_MAJOR, "xloop"); + misc_deregister(&xloop_misc); + + /* + * There is no need to use xloop_ctl_mutex here, for nobody else can + * access xloop_index_idr when this module is unloading (unless forced + * module unloading is requested). If this is not a clean unloading, + * we have no means to avoid kernel crash. + */ + idr_for_each_entry(&xloop_index_idr, xlo, id) + xloop_remove(xlo); + + idr_destroy(&xloop_index_idr); + +#ifdef CONFIG_DEBUG_FS + debugfs_remove(xloop_dbgfs_dir); +#endif + + pr_info("exit module\n"); +} + +module_init(xloop_init); +module_exit(xloop_exit); + +#ifndef MODULE +static int __init max_xloop_setup(char *str) +{ + max_xloop = simple_strtol(str, NULL, 0); + return 1; +} + +__setup("max_xloop=", max_xloop_setup); +#endif diff --git a/src/kernel/xloop_main_rhel_8.5.h b/src/kernel/xloop_main_rhel_8.5.h new file mode 100644 index 0000000..97c2654 --- /dev/null +++ b/src/kernel/xloop_main_rhel_8.5.h @@ -0,0 +1,104 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * loop_main.h + * + * Written by Theodore Ts'o, 3/29/93. + * + * Copyright 1993 by Theodore Ts'o. Redistribution of this file is + * permitted under the GNU General Public License. + */ +#ifndef _LINUX_XLOOP_H +#define _LINUX_XLOOP_H + +#include <linux/bio.h> +#include <linux/blkdev.h> +#include <linux/blk-mq.h> +#include <linux/spinlock.h> +#include <linux/mutex.h> +#include <linux/kthread.h> +#include "uapi_xloop.h" +#ifdef CONFIG_DEBUG_FS +#include <linux/debugfs.h> +#endif + +#include "xloop_file_fmt.h" + +/* Possible states of device */ +enum { + Xlo_unbound, + Xlo_bound, + Xlo_rundown, +}; + +struct xloop_func_table; + +struct xloop_device { + int xlo_number; + atomic_t xlo_refcnt; + loff_t xlo_offset; + loff_t xlo_sizelimit; + int xlo_flags; + int (*transfer)(struct xloop_device *xlo, int cmd, struct page *raw_page, + unsigned int raw_off, struct page *xloop_page, unsigned int xloop_off, + int size, sector_t real_block); + char xlo_file_name[XLO_NAME_SIZE]; + char xlo_crypt_name[XLO_NAME_SIZE]; + char xlo_encrypt_key[XLO_KEY_SIZE]; + int xlo_encrypt_key_size; + struct xloop_func_table *xlo_encryption; + __u32 xlo_init[2]; + kuid_t xlo_key_owner; /* Who set the key */ + int (*ioctl)(struct xloop_device *xlo, int cmd, unsigned long arg); + + struct xloop_file_fmt *xlo_fmt; + + struct file *xlo_backing_file; + struct block_device *xlo_device; + void *key_data; + + gfp_t old_gfp_mask; + + spinlock_t xlo_lock; + int xlo_state; + struct kthread_worker worker; + struct task_struct *worker_task; + bool use_dio; + bool sysfs_inited; + + struct request_queue *xlo_queue; + struct blk_mq_tag_set tag_set; + struct gendisk *xlo_disk; + +#ifdef CONFIG_DEBUG_FS + struct dentry *xlo_dbgfs_dir; +#endif +}; + +struct xloop_cmd { + struct kthread_work work; + bool use_aio; /* use AIO interface to handle I/O */ + atomic_t ref; /* only for aio */ + long ret; + struct kiocb iocb; + struct bio_vec *bvec; + struct cgroup_subsys_state *css; +}; + +/* Support for loadable transfer modules */ +struct xloop_func_table { + int number; /* filter type */ + int (*transfer)(struct xloop_device *xlo, int cmd, struct page *raw_page, unsigned int raw_off, + struct page *xloop_page, unsigned int xloop_off, int size, sector_t real_block); + int (*init)(struct xloop_device *xlo, const struct xloop_info64 *info); + /* release is called from xloop_unregister_transfer or clr_fd */ + int (*release)(struct xloop_device *xlo); + int (*ioctl)(struct xloop_device *xlo, int cmd, unsigned long arg); + struct module *owner; +}; + +extern inline struct device *xloop_device_to_dev(struct xloop_device *xlo); + +int xloop_register_transfer(struct xloop_func_table *funcs); +int xloop_unregister_transfer(int number); + +#endif |